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VoIP Subscriber Gateways
3.3.3
The ‘Kernel’ submenu
Use the submenu to view circular kernel buffer.
3.3.4 The ‘PCAP Traces’ submenu
The submenu makes it possible to capture network traffic from active interfaces of a
device.
The
‘Start traces’
section
:
‐
Interface
— a selector field used for assigning the interface for network traffic
capturing (only active interfaces are displayed);
‐
Filter
— network traffic filtering rules;
‐
The
‘Start’
button — a button to start network traffic capturing. If traffic
capturing has been started successfully, the following message is displayed:
«TCP-dump for interface `<ifacename>` is started. Otherwise, the message will
be like: «Can't start tcpdump». In most cases this is due to entering an incorrect
filter into the
‘Filter’
field;
‐
The ‘
Stop’
button — a button to stop network traffic capturing.
The ‘
Dump files’
section
contains the list of files that can be unloaded by pressing the
file name in the ‘
Name’
field. Unnecessary files can be removed by pressing
‘Remove’
.
Filter expression structure:
Each expression that specifies a filter includes one or more primitives that consist of one
or more object identifiers and classifiers preceding them. Object’s name or number can serve
as identifier.
Object classifiers:
1.
type
– specifies the type of the object assigned by the identifier. The
type
may accept
the following values:
